// Copyright (c) 2012 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "net/quic/quic_crypto_stream.h"

#include <string>

#include "base/strings/string_piece.h"
#include "net/quic/crypto/crypto_handshake.h"
#include "net/quic/crypto/crypto_utils.h"
#include "net/quic/quic_connection.h"
#include "net/quic/quic_session.h"
#include "net/quic/quic_utils.h"

using base::StringPiece;
using net::SpdyPriority;
using std::string;

namespace net {

#define ENDPOINT                                                                 \
    (session()->perspective() == Perspective::IS_SERVER ? "Server: " : "Client:" \
                                                                       " ")

QuicCryptoStream::QuicCryptoStream(QuicSession* session)
    : ReliableQuicStream(kCryptoStreamId, session)
    , encryption_established_(false)
    , handshake_confirmed_(false)
{
    crypto_framer_.set_visitor(this);
    // The crypto stream is exempt from connection level flow control.
    DisableConnectionFlowControlForThisStream();
}

void QuicCryptoStream::OnError(CryptoFramer* framer)
{
    DLOG(WARNING) << "Error processing crypto data: "
                  << QuicUtils::ErrorToString(framer->error());
}

void QuicCryptoStream::OnHandshakeMessage(
    const CryptoHandshakeMessage& message)
{
    DVLOG(1) << ENDPOINT << "Received " << message.DebugString();
    session()->OnCryptoHandshakeMessageReceived(message);
}

void QuicCryptoStream::OnDataAvailable()
{
    struct iovec iov;
    while (true) {
        if (sequencer()->GetReadableRegions(&iov, 1) != 1) {
            // No more data to read.
            break;
        }
        StringPiece data(static_cast<char*>(iov.iov_base), iov.iov_len);
        if (!crypto_framer_.ProcessInput(data)) {
            CloseConnectionWithDetails(crypto_framer_.error(),
                crypto_framer_.error_detail());
            return;
        }
        sequencer()->MarkConsumed(iov.iov_len);
    }
}

void QuicCryptoStream::SendHandshakeMessage(
    const CryptoHandshakeMessage& message)
{
    SendHandshakeMessage(message, nullptr);
}

void QuicCryptoStream::SendHandshakeMessage(
    const CryptoHandshakeMessage& message,
    QuicAckListenerInterface* listener)
{
    DVLOG(1) << ENDPOINT << "Sending " << message.DebugString();
    session()->OnCryptoHandshakeMessageSent(message);
    const QuicData& data = message.GetSerialized();
    // TODO(wtc): check the return value.
    WriteOrBufferData(StringPiece(data.data(), data.length()), false, listener);
}

bool QuicCryptoStream::ExportKeyingMaterial(StringPiece label,
    StringPiece context,
    size_t result_len,
    string* result) const
{
    if (!handshake_confirmed()) {
        DLOG(ERROR) << "ExportKeyingMaterial was called before forward-secure"
                    << "encryption was established.";
        return false;
    }
    return CryptoUtils::ExportKeyingMaterial(
        crypto_negotiated_params_.subkey_secret, label, context, result_len,
        result);
}

bool QuicCryptoStream::ExportTokenBindingKeyingMaterial(string* result) const
{
    if (!encryption_established()) {
        QUIC_BUG << "ExportTokenBindingKeyingMaterial was called before initial"
                 << "encryption was established.";
        return false;
    }
    return CryptoUtils::ExportKeyingMaterial(
        crypto_negotiated_params_.initial_subkey_secret, "EXPORTER-Token-Binding",
        /* context= */ "", 32, result);
}

const QuicCryptoNegotiatedParameters&
QuicCryptoStream::crypto_negotiated_params() const
{
    return crypto_negotiated_params_;
}

} // namespace net
